The datasource cited is **Land-Ocean Temperature Index, ERSSTv4, 1200km smoothing**, which can be found here https://data.giss.nasa.gov/gistemp/ .

In this notebook, we will take a first look at the GISTEMP temperature anomaly datasets. These datasest denote the temperature deviation with respect to a reference time periode. For the sake of this notebook, we will not concern ourselves with how the anomaly data is prepred. This is a story for another article.

This section deals with the module imports for this notebook. This section needs to complete for the notebook to work correctly.

My anaconda setup:

Python 3.5 environment

Anaconda notebook extension + community notebook extensions

conda-forge channel activated

In [2]:

importIPythonfromIPython.displayimportHTML,displayimportdatetimefromipywidgetsimportinteract,interactive,fixed,interact_manualimportipywidgetsaswidgetsimportscipyasspimportpandasaspdimportpylabaspltimportmatplotlib.mlabasmlabfrommatplotlib.datesimportdrange,MonthLocator%matplotlib notebook
# Modules to create nice colormaps and earth projectionstry:frommpl_toolkits.basemapimportBasemapimportcmoceanexceptExceptionasex:print('Module basemap,cmocean not installed, please use pip or conda to install basemap and cmocean')print(ex)importurllib.requestimportosimportsysimportgzipimportzipfileimportshutiltry:importplotlyimportplotly.plotlyaspyfromplotly.graph_objsimport*plotly.offline.init_notebook_mode(connected=True)#plotly.offline.init_notebook_mode()print('Plotly Version: ',plotly.__version__)except:print('Plotly not installed correctly')try:importnetCDF4exceptExceptionasex:print('netCDF4 is not correctly installed. Please us pip or conda to install.')print(ex)

The LOTI (Land-Ocean Temperature Index) uses a more complicated averaging scheme between the ocean and land data to account for the higher heat capactity of water. According to NASA this leads to a slight underestimation of cooling and warming trends due to the dampening effect of the oceans. The two input datasets for the LOTI calculations are:

Surface Air Temperatures (SATs) measured by weather stations worldwide, and

The units for the LOTI are in degC and denote the temperature deviation with respect to a referece temperature.Currently the reference temperature is the mean temperature from 1951 to 1980. Nasa calls this quantity the temperature anomaly.

Nasa executes the avaeraging procedure every month and make the resulting datafiles available. For this section, three files were analyzed:

The global mean fore each month since 1880: GLB.Ts+dSST.csv

The northern hemisphere mean for each month since 1880: NH.Ts+dSST.csv

The sourthern hemisphere mean for each month since 1880: SH.Ts+dSST.csv